article {
    width: 100%;
    height: 550px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: center;
}

.mid_img {
    width: 750px;
    height: 535px;
    background-image: url(../imgs/合作.png);
    background-repeat: no-repeat;
}
